Moderate reductions in dissolved oxygen may compromise performance in an ecologically-important estuarine invertebrate

摘要: Abstract Coastal ecosystems, including estuaries, are increasingly pressured by expanding hypoxic regions as a result of human activities such increased release nutrients and global warming. Hypoxia is often defined oxygen concentrations below 2 mL O2 L−1. However, taxa vary markedly in their sensitivity to hypoxia can be affected broad spectrum low levels. To better understand how reduced availability impacts physiological molecular processes invertebrates, we investigated responses an estuarine amphipod ecologically-relevant level moderate (~2.6 mL L−1) or severe (~1.3 mL L−1). Moderate elicited reduction aerobic scope, widespread changes gene expression, upregulation metabolic genes stress proteins. Under hypoxia, marked hyperventilatory response associated with maintenance performance was accompanied muted transcriptional response. This included return baseline levels expression downregulation transcripts involved protein synthesis, most which indicate recourse hypometabolism and/or impairment. We conclude that adverse ecological effects may occur under through compromised individual and, therefore, even modest declines future pose significant challenge coastal ecosystems.